Process for the manufacture of pulverulent detergent formulations containing sodium tripolyphosphate



United States Patent Int. 01. C11d3/06, 11/00 U.S. Cl. 252-135 6 Claims ABSTRACT OF THE DISCLOSURE Pulverulent washing, cleansing, rinsing and degreasing agents are produced by spraying a wash-active substance, in the presence of water, on sodium tripolyphosphate having a bulk density higher than 550 grams/liter, preferably higher than 600 up to 700 grams/liter, and containing 20 to 100% by weight, preferably 40 to 80% by weight phase-I material. Flowa'ble material free from stickiness is obtained.

The present invention relates to a process for the manufacture of pulverulent washing, cleansing, rinsing and degreasing agents, wherein a wash-active substance is sprayed on sodium tripolyphosphate.

It has already been suggested in the art that either anionoor non-ionogenic wash-active substances may be sprayed on voluminous alkali metal phosphates, particularly pyrophosphates. This procedure calls for the use of alkali metal phosphates with a bulk density lower than 550 grams/liter, because phosphates with a higher bulk density have been found unable to bind the necessary quantity of wash-active substance, and also to form undesired clotty products.

The process of the present invention, wherein washactive substances are sprayed, in the presence of water, on sodium tripolyphosphate having a bulk density higher than 550 grams/liter, preferably higher than 600 up to about 700 grams/ liter, and containing phase-I material in a proportion of 20 to 100% by weight, preferably 40 to 80% by weight, has now unexpectedly been found to be free from the disadvantages mentioned above. The present process has also been found to offer various advantages over conventional methods. The conventional methods are found to be generally applicable only to pyrophosphates, to require the wash-active substance to be sprayed very slowly in the form of droplets which are not allowed to exceed a certain diameter, and to require the final product to be dusted subsequently with a finely pulverulent absorbent. The process of the present invention, on the other hand, can be carried out on a commercial scale using sodium tripolyphosphate which is a preferred detergent component considering its high power of binding lime. In the present process, the sodium tripolyphosphate used as the builder can very readily be sprayed with the wash-active substances of either anionic, cationic or nonionic nature which, for example,

include the following anionic representatives:

alkyl aryl sulfonates, true soaps (alkali metal salts of saturated and unsaturated fatty acids, for example oleic acid, palmitic acid, stearic acid, behenic acid, coconut oil fatty acid, tallow fatty acid, palm-kernel oil fatty acid or other acids produced from natural oils and fats); salts of aminocarboxylic acids; salts of highor low-acylated aminocarboxylic acids; fatty acid sulfates; sulfates or phosphates of fatty acid esters or amides; primary and secondary alkyl sulfates or sulfonates; sulfates, sulfonates or phosphates of esterified or etherified polyoxy compounds; sulfates, sulfonates or phosphates of substituted polyglycol ethers;

include the following nonionic representatives:

esters or ethers of polyalcohols; alkyl, acyl or alkyl aryl polyglycol ethers; and

include the following cation-active representatives:

alkylamine salts; quaternary ammonium salts; alkyl pyridinium salts; ordinary and quaternary imidazonline salts; alkyl diamines and polyamines.

Generally, these wash-active substances are conveniently used in the form of an aqueous solution or paste. In the event that nonionic wash-active substances, which are generally found to be practically anhydrous, are used, they should be employed in combination with about 1 to 22% by weight water, referred to the sodium tripolyphosphate, the water being sprayed on the sodium tripolyphosphate through a second nozzle separate from that used for spray ing the nonionic substance.

Further and more important advantages reside in the greater hydration velocity of sodium tripolyphosphate formed of phase-I material. This means that the washactive substances can be sprayed much more rapidly, that mixing vessels of considerably enlarged capacity can be used for making the washing agents, etc., and that the sprayed phosphate need not be dusted subsequently with absorbent.

The spraying can be achieved inside any mixer provided with means for the nozzle spraying of a liquid or paste.

The use of phase-I-containing sodium tripolyphosphates having a bulk density higher than 550 grams/liter is also of importance inasmuch as high bulk density is a factor desirable for a plurality of applications, for example for the production of pulverulent rinsing agents for use in automatic dish washing machines. These often have dosing means of limited dimensions. In other words, heavy powders are needed to fill the dosing means with the quantity of dish rinsing agent necessary for the rinsing operation.

The following examples illustrate the process of the present invention.

EXAMPLE 1 EXAMPLE 2 Sodium tripolyphosphate containing 60% phase-I material and having a bulk density of 630 grams/liter was sprayed with 40% by weight alkyl aryl sulfonate in a 65% aqueous solution, the percentages being referred to the tripolyphosphate. The fiowable final product had a bulk density of 500 grams/liter. The same proportion of alkyl aryl sulfonate was sprayed by way of comparison on phase-II sodium tripolyphosphate having a bulk density of 650 grams/liter. The final product so obtained was found to be sticky and not flowable.

, 3 We claim:

1. A process for preparing pulverulent washing and degreasing agents containing:

(A) sodium tripolyphosphate builder and (B) a compound selected from the group consisting of anionic, cationic and nonionic organic detergents and mixtures thereof; comprising spraying the (B) component in the presence of water onto the (A) component, said (A) component being sodium tripolyphosphate containing about 20100% by weight of phase-I material and having a bulk density greater than 550 grams/liter.

2. The process of claim 1, wherein the anionic and cationic detergents are used in the form of an aqueous solution.

3. The process of claim 1, wherein the anionic and cationic detergents are used in the form of an aqueous paste.

4. The process of claim 1, wherein nonionic detergents are used in combination with 1 to 22% by weight water,

referred to the sodium tripolyphosphate, the water being sprayed on the sodium tripolyphosphate through a nozzle 4 separate from that used for spraying the nonionic detergents.

5. The process of claim 1 wherein the (A) component has a bulk density of about 600-700 grams/liter.

6. The process of claim 1 wherein the (A) component contains to by weight phase-I material.

References Cited UNITED STATES PATENTS 2,308,992 1/ 1943 Mertens 25297 FOREIGN PATENTS 443,731 3/1936 Great Britain.

438,063 11/1935 Great Britain.

HERBERT B. GUYNN, Primary Examiner D. L. ALBRECHT, Assistant Examiner US. Cl. X.R. 

